π Materials β
Everything in the model needs a material. Alpaca4d has two families, and they are not interchangeable β a component that wants one will refuse the other.
| Family | For | Component |
|---|---|---|
| Uniaxial | 1D stressβstrain. Beam sections, fibres, hinges. | Uniaxial |
| nD | The full 2D/3D stressβstrain law at a Gauss point. Shells, bricks, tetrahedra. | nD |
Both can also be pulled from the Material Database, which fills in standard grades of steel, concrete, timber and plastic so you do not have to type E, G, Ξ½ and Ο by hand.
For the non-linear materials used by fibre sections β Concrete01, Steel01, ReinforcingSteel β see Moment Curvature.
Which goes where β
| You are building | Give it |
|---|---|
| A beam cross-section (rectangle, circle, I, 2L, hollow, generic) | a Uniaxial material |
| A Plate Fiber Section for shells | an nD material |
| An SSP Brick or Tetrahedron | an nD material |
| A fibre in a Fiber Section | a Uniaxial material |
Units β
E, G and stresses are in kN/mΒ²; density Rho is in kg/mΒ³; strains and Poisson's ratios are dimensionless.